Absorber of absorption system refrigerator

ABSTRACT

The absorber for use in absorption chillers of the present invention comprises a plurality of cooling water pipes  2  extending horizontally in the interior of the absorber chamber. A plurality of flat heat transfer plates  1  are spaced apart from one another and arranged horizontally in a vertical position, and the plurality of cooling water pipes  2  extend through these heat transfer plates  1  perpendicular thereto. The pitch Pd of the plates  1  is 3 to 15 mm. Each heat transfer plate  1  is integrally formed on its upper end face with an absorbent receptacle  10  V-shaped in cross section and extending longitudinally of the upper end face. The bottom portion of the receptacle  10  is formed with two rows of absorbent holes  11  positioned upwardly of respective surfaces of the plate  1 . The holes  11  of each row are spaced apart from one another longitudinally of the plate  1  and each have an outlet adjoining the surface of the plate  1 . This enables an absorber to have a higher absorbing capacity than conventional absorbers.

TECHNICAL FIELD

The present invention relates to absorbers for use in absorptionchillers for causing an absorbent to absorb a vapor of refrigerantproduced by an evaporator.

BACKGROUND ART

With reference to FIG. 17, double-effect absorption chillers have aclosed drum 3 provided in its interior with an eliminator 30, and anevaporator chamber 31 and an absorber chamber 32 which are arranged atopposite sides of the eliminator 30. An evaporator (not shown) isdisposed in the evaporator chamber 31, and an absorber 50 in theabsorber chamber 32. Connected to the bottom of the closed drum 3 ispiping 62 extending to a high-temperature generator via alow-temperature heat exchanger and a high-temperature heat exchanger,with an absorbent pump 6 mounted on an intermediate portion of thepiping 62.

The absorber 50 comprises an absorbent sprinkler 4 connected to one endof piping 61 extending from the low-temperature heat exchanger, and acooling water piping system comprising a plurality of cooling waterpipes 2 extending horizontally.

In the absorber 50, an absorbent (aqueous solution of lithium bromide)is scattered on the cooling water pipes 2 by the sprinkler 4 asindicated in broken lines. During falling, the absorbent absorbs a vaporof refrigerant produced by the evaporator, has its temperature raised bythe heat of condensation and heat of mixing (heat of absorption) thengenerated, and is cooled with cooling water flowing through the pipes 2.

The absorbent scattered by the sprinkler 4 in the conventional absorber50 first falls onto the outer peripheral surfaces of the cooling waterpipes 2 at the uppermost stage, flows down the peripheral surfaces inthe form of drops and thereafter falls onto the outer peripheralsurfaces of the cooling water pipes 2 at the next lower stage. In thisway, the absorbent is delivered in the form of drops to the pipes 2 fromstage to stage downward. Accordingly, the absorbent not only falls at arelatively high speed under gravity but also fails to sufficientlyspread over the outer peripheral surfaces of the pipes 2, and thereforehas a small area for absorbing the refrigerant vapor and wets the pipesurfaces over small areas. The absorber consequently has the problem ofbeing low in absorbing capacity due to insufficient absorption and heatexchange.

Accordingly, an object of the present invention is to provide anabsorber having a higher absorbing capacity than conventional absorbers.

DISCLOSURE OF THE INVENTION

The present invention provides an absorber for use in absorptionchillers which has a closed chamber to be supplied with an absorbent anda refrigerant vapor and having installed therein means for supplying theabsorbent. For example, the conventional absorbent sprinkler 4 is usableas the absorbent supplying means. Positioned below the absorbentsupplying means is a cooling water piping system comprising a pluralityof cooling water pipes which extend horizontally and are interconnectedin series or in parallel. A plurality of platelike heat transfer bodiesare spaced apart from one another and arranged in a vertical positionhorizontally. The cooling water pipes extend through these heat transferbodies.

With the absorber described for use in absorption chillers, coolingwater is supplied to the pipes to cool the surfaces of the heat transferbodies and the pipes with the water to a sufficiently loweredtemperature.

The absorbent is supplied by the absorbent supplying means to thesurfaces of the heat transfer bodies. The absorbent then flows down thesurfaces of the heat transfer bodies and the outer peripheral surfacesof the cooling water pipes while spreading over the surfaces of the heattransfer bodies. While flowing in this way, the absorbent absorbs avapor of refrigerant passing between the heat transfer bodies by cominginto contact with the refrigerant vapor over a sufficient area.

While flowing down the surfaces of the heat transfer bodies, theabsorbent wets these surfaces over large areas. Moreover, the absorbentis slowed down by flow resistance and therefore flows down the surfacesof the heat transfer bodies over a sufficient period of time. Thiseffects sufficient heat exchange with these surfaces, whereby theabsorbent is effectively cooled.

Thus, the absorbent comes into contact with the refrigerant vapor over alarge area for the absorption of the vapor, and the resulting heat iseffectively removed by sufficient heat exchange. As a result, a highabsorbing capacity is available.

Stated more specifically, each of the heat transfer bodies comprises asingle heat transfer plate.

According to another specific embodiment, the cooling water pipes arearranged in a plurality of stages spaced apart from one anothervertically, and each of the heat transfer bodies comprises a pluralityof heat transfer plates each of which is provided for one or at leasttwo stages of the pipes.

The heat transfer plates extend horizontally. The upper of each pair ofheat transfer plates which are vertically adjacent to each other has alower end spaced apart by a predetermined clearance from the upper endof the lower of the pair. The clearance is preferably 2 mm to 3 mm. Eachheat transfer plate has one or at least two stages of cooling waterpipes extending therethrough. All the heat transfer plates or the heattransfer plates other than the plate at the uppermost position each havean upper end face positioned at the same level as or approximately thesame level as upper ends of outer peripheral surfaces of the coolingwater pipes positioned at the uppermost stage and extending through theheat transfer plate.

With the absorber having the construction described, the absorbent issupplied by the absorbent supplying means to the surface of each of theuppermost heat transfer plates and thereafter flows down the surfaces ofheat transfer plates and the outer peripheral surfaces of cooling waterpipes. In this process, the absorbent flowing down the outer peripheralsurface of one pipe will partly fall off that pipe to flow down thesurface of the plate. At this time, the portion of absorbent thusflowing will combine with a downflow portion of the absorbent fallingoff another pipe laterally adjacent to the above-mentioned pipe. Theconfluent flow will then pass between two cooling water pipes arrangedat the next lower stage.

Even when such a flow of absorbent occurs in the absorber, the absorbentpartly spreads leftward and rightward along the lower end face of oneheat transfer plate or along the upper end face of another heat transferplate positioned therebelow upon the absorbent flow reaching the platelower end face. The absorbent then reaches the upper end of outerperipheral surface of one of the uppermost cooling water pipes extendingthrough the lower heat transfer plate, whereupon the absorbent flowsdown along the pipe outer peripheral surface.

The absorbent flowing down the surfaces of the heat transfer plates andthe outer peripheral surfaces of the cooling water pipes spreads asdescribed above every time the absorbent passes across the clearancebetween the plates, to flow down as fully spread not only over the platesurfaces and also over the pipe outer peripheral surfaces. As a result,the heat transfer plates, i.e., the platelike heat transfer bodies,produce the effect described, while the cooling water pipes fullyexhibit a direct cooling effect to result in a high absorbing capacity.

Stated specifically, the platelike heat transfer bodies are arrangedwith a pitch of 3 mm to 15 mm.

While flowing down the surfaces of the heat transfer bodies, theabsorbent absorbs the refrigerant vapor passing between the heattransfer bodies by coming into contact with the vapor. As the pitch ofthe heat transfer bodies decreases, the portions of absorbent flowingdown the opposed surfaces of each pair of adjacent heat transfer bodiesapproach each other. These absorbent portions combine to flow down ifthe pitch becomes smaller than 3 mm, consequently blocking the flowchannel of the refrigerant vapor. The refrigerant vapor then fails tocontact the absorbent over a sufficient area to result in a greatlyimpaired absorbing capacity.

Further as the pitch of the heat transfer bodies increases, the numberof heat transfer bodies arranged over the entire length of the coolingwater pipes decreases, reducing the refrigerant vapor absorbing area ofthe absorbent and the area of the heat transfer bodies wetted with theabsorbent (the area, m², of contact between the surfaces of the heattransfer bodies and the absorbent adhering to the surfaces). When thepitch exceeds 15 mm, it is impossible to obtain an amount of absorptionand an amount of heat exchange which are much greater than thoseobtained by the conventional absorber having no platelike heat transferbodies.

Accordingly, it is desired that the pitch of the heat transfer bodies bein the range of 3 to 15 mm.

Stated more specifically, each heat transfer body is in the form of aplate corrugated in a vertical direction. Alternatively the heattransfer body is subjected to surface working and thereby formed withridges and furrows arranged along a vertical direction.

When thus shaped, the heat transfer body offers increased flowresistance to the downflow of the absorbent, giving a smaller flow rateto the absorbent than the heat transfer body in the form of a flatvertical plate, affording an increased absorbing area to the absorbentand enabling the absorbent to wet the heat transfer body over anincreased area, whereby an increased amount of absorption and a largeramount of heat exchange can be obtained.

Further stated more specifically, each heat transfer body is formed witha plurality of vapor passing apertures positioned away from the outerperipheries of the cooling water pipes.

The refrigerant vapor supplied to the closed chamber is then caused toflow through the heat transfer body by way of the vapor passingapertures in addition to the flow along the heat transfer body.Accordingly, the refrigerant vapor uniformly flows through the closedchamber without being impeded by the heat transfer bodies and becomesfully absorbed by the absorbent.

Further stated more specifically, the absorbent supplying meanscomprises a downflow distributor for allowing the absorbent to flow downthe plurality of heat transfer bodies, and a feeder for supplying theabsorbent to the downflow distributor. The downflow distributorcomprises an absorbent receptacle for retaining therein the absorbent tobe allowed to flow downward. The receptacle has a bottom formed with aplurality of absorbent holes for causing the absorbent to flow downtherethrough. The absorbent holes each have an outlet positioned inproximity to the surface of the heat transfer body.

The absorbent is supplied to the downflow distributor from the feeder ofthe absorbent supplying means thus constructed. The absorbenttemporarily remains in the receptacle of the downflow distributor andthen flows out of the outlets of the absorbent holes. The absorbentflowing out of the outlets of the holes immediately flows along thesurfaces of the heat transfer bodies and further flows down thesesurfaces and the outer peripheral surfaces of the cooling water pipeswhile spreading over the transfer body surfaces. The absorbent flowingdown from the absorbent receptacle wholly flows downward along thetransfer body surfaces.

If the absorber is not provided with the downflow distributor, on theother hand, the absorbent supplied from above the heat transfer bodiestoward these bodies is likely to partly flow dropwise between each pairof opposed heat transfer bodies along the water pipes at the uppermoststage and then along lower water pipes from stage to stage downwardwithout flowing down the transfer bodies.

With the absorber having the construction described above, a largeramount of absorbent flows down the surfaces of the heat transfer bodiesthan in the absence of the downflow distributor, giving the absorbent anincreased absorbing area and permitting the absorbent to wet anincreased area. As a result, an increased amount of absorption and alarger amount of heat exchange are available.

Further stated more specifically, the absorbent receptacle is providedfor each heat transfer body as joined to the upper end face thereof andextends longitudinally of the upper end face.

Since the absorbent receptacle is thus joined to each heat transfer bodyto form a unit, the number of heat transfer bodies can be altered indesigning the absorber merely by varying the number of units, and thereis no need to determine the size and shape of the downflow distributoragain in accordance with the number. Accordingly, the absorber is easyto alter in design.

According to another specific embodiment, the absorbent receptacle ofthe downflow distributor is connected to all the platelike heat transferbodies across the upper ends thereof and dimensioned to contain theupper ends of all the heat transfer bodies.

According to this construction, at least one absorbent supply pipe maybe connected to the absorbent receptacle. Thus, the feeder can beprovided by the single absorbent supply pipe and is simplified inconstruction.

Stated more specifically, the absorbent holes of the downflowdistributor are each in the form of a slit having an outlet extendingalong the surface of the heat transfer body.

The absorbent then remaining in the absorbent receptacle of the downflowdistributor flows out of each absorbent hole in the form of a thin filmand flows down as spread over the surface of the heat transfer body. Thestructure described therefore gives the absorbent an increased absorbingarea and permits the absorbent to wet an increased area, with the resultthat an increased amount of absorption and a larger amount of heatexchange can be obtained.

As compared with conventional absorbers, the absorber embodying thepresent invention for use in absorption chillers enables the absorbentto contact the refrigerant vapor over a larger area for the absorptionof the vapor, while the resulting heat can be removed effectively bysufficient heat exchange. The present absorber therefore has aremarkably improved absorbing capacity.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a fragmentary perspective view partly broken away and showingan absorber of first embodiment;

FIG. 2 is a front view showing an arrangement of cooling water pipesincluded in the absorber;

FIG. 3 is a side elevation showing an arrangement of heat transferplates included in the absorber;

FIG. 4 is a graph showing the results of calculations relating to theabsorbing capacity and performed to substantiate the effect of theinvention;

FIG. 5 is a sectional view showing the shapes of heat transfer platesand cooling water pipes used for the calculations;

FIG. 6 is a fragmentary perspective view partly broken away and showingan absorber of second embodiment;

FIG. 7 is a front view showing an arrangement of cooling water pipesincluded in the absorber;

FIG. 8 is a side elevation showing an arrangement of heat transferplates included in the absorber;

FIG. 9 is a front view showing another arrangement of cooling waterpipes;

FIG. 10 is a side elevation showing heat transfer plates of differentshape;

FIG. 11 includes sectional views showing heat transfer plates which aredifferent in sectional shape;

FIG. 12 is a perspective view partly broken away and showing anotherexample of structure having absorbent holes for use in the absorber ofsecond embodiment;

FIG. 13 is a fragmentary perspective view partly broken away and showingan absorber of third embodiment;

FIG. 14 is a diagram showing the sizes and pitches of vapor passingapertures and cooling water pipe insertions holes formed in a heattransfer plate;

FIG. 15 is a fragmentary sectional view showing an absorber of fourthembodiment;

FIG. 16 is a graph showing the relationship between the absorbent flowrate and the refrigerating capacity; and

FIG. 17 is a diagram showing an absorber installed in a closed drum andincluded in a double-effect absorption chiller.

BEST MODE OF CARRYING OUT THE INVENTION

Absorbers embodying the present invention for use in double-effectabsorption chillers will be described below in detail with reference tothe drawings.

First Embodiment

The absorber of this embodiment, like the conventional one shown in FIG.17, is installed in the absorber chamber 32 of the closed drum 3.

With reference to FIGS. 1 to 3, the absorber 5 of this embodimentcomprises a plurality of cooling water pipes 2 extending horizontallyand arranged with a pitch, for example, of 22 mm both vertically andhorizontally in the interior of the absorber chamber 32. A plurality offlat heat transfer plates 1 are spaced apart from one another andarranged horizontally in a vertical position, and the plurality ofcooling water pipes 2 extend through these heat transfer plates 1perpendicular thereto. A flat copper sheet having a thickness Td of 0.5mm or the like is usable for the heat transfer plates 1. Alternatively,other known material, such as a sheet of aluminum or the like, is usablefor the heat transfer plates 1. The pitch Pd of the plates 1 is 3 to 15mm.

Each heat transfer plate 1 is integrally formed on its upper end facewith an absorbent receptacle 10 V-shaped in cross section and extendinglongitudinally of the upper end face. The bottom portion of thereceptacle 10 is formed with two rows of absorbent holes 11 positionedupwardly of respective surfaces of the plate 1. The holes 11 of each roware spaced apart from one another longitudinally of the plate 1 and eachhave an outlet adjoining the surface of the plate 1. The absorbentreceptacles 10 formed on the respective heat transfer plates 1 provide adownflow distributor.

With the absorber 5 for use in absorption chillers, cooling water issupplied to the pipes 2 to cool the surfaces of the plates 1 and thepipes 2 with the water to a sufficiently lowered temperature.

The absorbent is supplied from the piping 61 shown in FIG. 17 to thereceptacles 10 of the present embodiment shown in FIG. 1. The absorbenttemporarily remains in each receptacle 10 and then flows out of theoutlets of the holes 11. The absorbent flowing out of the outlets of theholes 11 immediately flows along the surfaces of the heat transfer plate1 as indicated by arrows of two-dot chain lines and further flows downthe plate surfaces and the outer peripheral surfaces of the pipes 2while spreading over the plate surfaces. The absorbent flowing down fromthe absorbent receptacle 10 wholly flows downward along the platesurfaces without dripping that occurs in the prior art.

While flowing down the surfaces of the heat transfer plates 1, theabsorbent absorbs the refrigerant vapor passing between the plates 1 bycoming into contact with the refrigerant vapor over a sufficient area.In the meantime, the absorbent wets the surfaces of the plates 1 overlarge areas. Moreover, the absorbent is slowed down by flow resistanceand therefore flows down the surfaces of the heat transfer plates 1 fromtheir upper ends to the lower ends thereof over a sufficient period oftime, whereby a large amount of heat is exchanged.

In this way, the absorbent comes into contact with the refrigerant vaporover a large area for the absorption of the vapor, and the resultingheat is effectively removed by sufficient heat exchange, whereby a highabsorbing capacity can be obtained.

FIG. 4 shows the results of calculations relating to the absorbingcapacity and performed to substantiate the effect of the invention.Potted as abscissa is the pitch Pd of the heat transfer plates 1, and asordinate is the ratio (V1/V2) of the volume V1 of the absorber 5 of theinvention to the volume V2 of the conventional absorber 50 having thesame absorbing capacity as the former. The smaller this ratio, thehigher the absorbing capacity of the absorber 5 of the invention.

Volume ratios were calculated using varying values for the pitch Pd ofheat transfer plates 1 and assuming that as seen in FIG. 5, thethickness Td of the heat transfer plates 1 was 0.5 mm, the outsidediameter Dt of the cooling water pipes 2 was {fraction (1/2 )}inch or{fraction (5/8 )}inch, the wall thickness Tt of the pipes 2 was 0.6 mmand the flow rate of the cooling water through the pipes 2 was 11.7 m/s.The solid circles plotted on FIG. 4 represent the results obtained whenthe outside diameter Dt of the pipes 2 was {fraction (1/2 )}inch, andthe blank circles those obtained when the outside diameter Dt was{fraction (5/8 )}inch.

As illustrated, the volume ratio has a minimum value of about 30% whenthe plate pitch Pd is 3 mm both in the case where the pipe outsidediameter Dt is {fraction (1/2 )}inch and in the case where the diameterDt is {fraction (5/8 )}inch.

It is also seen that the volume ratio increases gradually as the pitchPd increases from 3 mm. With a pitch Pd of 15 mm, the volume ratio isabout 95% when the pipe outside diameter Dt is {fraction (1/2 )}inch orabout 80% when the diameter Dt is {fraction (5/8 )}inch. The reason isthat as the pitch Pd of the plates 1 increases, the number of heattransfer plates 1 arranged over the entire length of the cooling waterpipes 2 decreases, reducing the absorbing area of the absorbent and thearea (m²) of the plates 1 wetted with the absorbent. When the pitch Pdexceeds 15 mm, the absorber of the invention has nearly the same wettedarea as the conventional absorber 50 having no heat transfer plates 1,failing to give an amount of heat exchange much greater than isconventionally available.

Incidentally, FIG. 4 reveals that the volume ratio markedly increaseswhen the plate pitch Pd is smaller than 3 mm because the arrangement ofheat transfer plates 1 as positioned closer to one another permits theportions of absorbent flowing down each pair of opposed surfaces to comeinto contact with each other to flow down as a confluent, which blocksthe flow channel of the refrigerant vapor. Consequently, the refrigerantvapor fails to contact the absorbent over a sufficient area to result ina greatly impaired absorbing capacity.

Accordingly, it is desired that the pitch Pd of heat transfer plates 1be in the range of 3 to 15 mm.

The graph of FIG. 4 reveals that since the absorber 5 of the presentembodiment is given a higher absorbing capacity than the conventionalabsorber 50, the volume required for the desired absorbing capacity canbe smaller, making it possible to compact the absorber 5.

Second Embodiment

Whereas the absorber 5 of the first embodiment has the absorbentreceptacles 10 integral with the upper end faces of the respective heattransfer plates 1 and serving as a downflow distributor, the absorber 7of this embodiment has a single absorbent receptacle 8 connected to allheat transfer plates 1 across the upper ends thereof and serving as adownflow distributor.

Stated more specifically with reference to FIGS. 6 to 8, a dishlikeabsorbent receptacle 8 is attached to all heat transfer plates 1 acrossthe upper ends thereof, that is, the upper ends of the heat transferplates 1 extend through the bottom wall of the absorbent receptacle 8.The bottom wall of the absorbent receptacle 8 has slitlike absorbentholes 81, 81 formed at opposite sides of each heat transfer plate 1 andextending along opposite surfaces of the plate 1.

In this way, the absorbent receptacle 8 extending across the upper endsof all the heat transfer plates 1 is installed as the downflowdistributor.

With the absorber 7 for use in absorption chillers, the surfaces of theheat transfer plates 1 and cooling water pipes 2 are cooled with thecooling water through the pipes 2 to a sufficiently lowered temperatureas in the first embodiment described.

The absorbent is supplied from the piping 61 shown in FIG. 17 to thereceptacle 8 of the present embodiment shown in FIG. 6. The absorbenttemporarily remains in the receptacle 8 and then flows out along thesurfaces of the heat transfer plates 1 via the holes 81. The absorbentflows out of each hole 81 in the form of a thin film at this time andtherefore flows down the surface of the plate 1 while wetting thesurface over the entire width thereof. Accordingly, the secondembodiment is greater than the first embodiment in the absorbing area ofthe absorbent and the wetted areas of the surfaces of the heat transferplates 1.

The second embodiment can consequently be given a higher absorbingcapacity than the first embodiment.

Third Embodiment

As shown in FIG. 13, the absorber 70 of this embodiment has a pluralityof vapor passing apertures 12 formed in each of the same heat transferplates 1 as in the first embodiment.

Cooling water pipes 2 have an outside diameter of 15.9 mm and a lengthof 2070 mm, are arranged in 17 vertical rows and 18 horizontal rows, andare 306 in total number. On the other hand, the heat transfer plates 1measure 396 mm ×374 mm ×0.5 mm, are 345 in number and are arranged witha pitch of 6 mm.

As shown in FIG. 14, the vapor passing apertures 12 have an insidediameter of 10 mm and are formed with the same pitch as cooling waterpipe insertion holes 13, i.e., 22 mm.

According to the first and second embodiments described, the absorbentsupplied from the absorbent receptacle 10 flows down while wetting thesurface of the heat transfer plate 1, and the plate 1 produces theforegoing effect over a surface area wetted by the spread of absorbent,whereas the plate 1 fails to fully exhibit the effect over the othersurface area unwet with the absorbent.

Accordingly, with attention directed to the occurrence of the unwetsurface area of the heat transfer plate 1, the vapor passing apertures12 are formed in the plate 1 to cause the refrigerant vapor to flowthrough the plate 1. Thus, the apertures 12 permit the refrigerant vaporto uniformly flow through the closed chamber 32 without being impeded bythe heat transfer plates 1 and to become fully absorbed by theabsorbent.

Fourth Embodiment

In the first to third embodiments described, the absorbent wetting theouter peripheral surface of the cooling water pipe 2 will partly falloff the pipe 2 to flow down the surface of the heat transfer plate 1.While thus flowing downward, this portion of absorbent will combine witha downflow portion of the absorbent falling off another cooling waterpipe 2 laterally adjacent to the above-mentioned pipe. The confluentflow will then pass between two cooling water pipes 2, 2 arranged at thenext lower stage. If the absorbent flows in this way over a wide area ofthe heat transfer plate 1, this portion of absorbent does not flow overthe water pipe 2 and therefore diminishes the direct cooling effect tobe produced by the water pipes 2 although the foregoing effect of theheat transfer plate 1 is available. This results in the likelihood thatthe desired absorbing capacity expected of the first to the thirdembodiments will not be obtained.

For use in the absorber 51 of this embodiment, the heat transfer plate 1is replaced by a plurality of heat transfer plates 9 which extendhorizontally as shown in FIG. 15.

These heat transfer plates 9 are arranged one above another in avertical plane and spaced apart from one another by a clearance G of 2to 3 mm. Each plate 9 has upper and lower two stages of cooling waterpipes 2 extending therethrough. The heat transfer plates 9 other thanthe plate 9 at the uppermost position each have an upper end facepositioned at the same level as the upper ends of outer peripheralsurfaces of the cooling water pipes 2 of the upper stage extendingthrough the plate 9. With the exception of the feature described above,the fourth embodiment is the same as the first embodiment shown in FIG.1. An absorber receptacle 10 is joined to the upper end face of theuppermost plate 9.

With the absorber thus having the absorber receptacle 10 at the upperend face of the uppermost heat transfer plate 9, it is desired that theupper end face of each of the heat transfer plates 9 in the secondhighest and lower positions other than the uppermost plate 9 be at thesame level as the upper ends of outer peripheral surfaces of the coolingwater pipes 2 of the uppermost stage extending through the plate 9. Onthe other hand, when the absorber has the conventional sprinkler 4 asabsorbent supplying means but no absorbent receptacle 10, the upper endface of each of all the heat transfer plates 9 including the uppermostplate 9 can be at the same level as the upper ends of outer peripheralsurfaces of the uppermost water pipes 2 extending through the plate 9.Alternatively, the upper end face of each of the heat transfer plates 9in the second highest and lower positions other than the uppermost plate9 can be at the same level as the upper ends of outer peripheralsurfaces of the water pipes 2 of the uppermost stage extending throughthe plate 9 as in the above case.

In the absorber 51 of this embodiment, the absorbent transfers from eachabsorbent receptacle 10 to the surface of the heat transfer plate 9 viathe absorbent holes 11 and then flows down the surfaces of the plate 9and the cooling water pipes 2. In this process, the absorbent will flowbetween two adjacent water pipes 2, 2 or form a confluent flow afterflowing over these pipes 2, 2 as indicated by arrows of two-dot chainlines in FIG. 15. Even if flowing in this way, the absorbent partlyspreads leftward and rightward along the lower end face of the heattransfer plate 9 or along the upper end face of another heat transferplate 9 positioned therebelow upon the absorbent flow reaching the platelower end face. The absorbent then reaches the upper ends of outerperipheral surfaces of cooling water pipes 2, whereupon the absorbentflows down along the pipe outer peripheral surface.

The absorbent thus flowing down the surfaces of heat transfer plates 9and the outer peripheral surfaces of water pipes 2 spreads as describedabove every time the absorbent passes across the clearance between theplates 9, to flow down as fully spread not only over the plate 9 andalso over the outer peripheral surfaces of water pipes 2. As a result,the heat transfer plates 9 produce the effect described, and the coolingwater pipes 2 exhibit a sufficient cooling effect to result in a highabsorbing capacity.

An absorber A of the first embodiment, an absorber B of the fourthembodiment and a conventional absorber C having no heat transfer platewere prepared as compact experimental devices of the same volume, andchecked for the relationship between the absorbent flow rate and therefrigerating capacity. The relationships determined, which are shown inFIG. 16, are represented by a broken line for the absorber A of thethird embodiment, by a chain line for the absorber B of the fourthembodiment , and by a solid line for the conventional absorber C. Theresults shown in FIG. 16 are obtained by calculating the refrigeratingcapacities and absorbent flow rates of the absorbers A, B and C havingthe foregoing characteristics, based on the refrigerating capacities andabsorbent flow rates determined by the experimental devices.

FIG. 16 reveals that the absorber A of the third embodiment having theheat transfer plates 1 formed with vapor passing apertures 12 is greaterin refrigerating capacity than the conventional absorber C regardless ofthe absorbent flow rate.

The absorber B of the fourth embodiment having the heat transfer plates9 is still greater than the absorber A of the third embodiment inrefrigerating capacity.

The absorber of the present invention is not limited to the foregoingembodiments in construction but can be modified variously within thetechnical scope defined in the appended claims.

For example, the cooling water pipes 2 used in the first to fourthembodiments can be in a staggered arrangement as shown in FIG. 9.

In place of the flat heat transfer plate 1 or 9, it is possible to use aheat transfer plate 90 which is in the form of a plate corrugated in avertical direction as shown in FIG. 10. Alternatively it is possible touse a heat transfer plate 91 which is subjected to surface working andthereby formed with ridges and furrows arranged along a verticaldirection as shown in FIG. 11, (a) to (c). Use of such heat transferplates 90 or 91 offers increased flow resistance to the downflow ofabsorbent to result in a lower flow rate, gives the absorbent a greaterabsorbing area and permits the absorber to wet the plate over a largerarea than when the heat transfer plates 1 or 9 are used which are eachin the form of a vertical flat plate, hence a higher absorbing capacity.

The absorbent hole 81 in the form of a slit and formed in the bottomportion of the absorbent receptacle shown in FIG. 6 can be replaced by aplurality of semicircular absorbent holes 82 shown in FIG. 12.

Further the vapor passing aperture 12 shown in FIG. 13 need not alwaysbe circular in form but can be, for example, in the form of a slit whichis elongated vertically.

What is claimed is:
 1. An absorber for use in absorption chillers whichhas a closed chamber to be supplied with an absorbent and a refrigerantvapor and having installed therein means for supplying the absorbent, acooling water piping system positioned below the absorbent supplyingmeans and comprising a plurality of cooling water pipes, the coolingwater pipes extending horizontally and being arranged in a plurality ofstages spaced apart from one another vertically, the cooling water pipesbeing interconnected in series or in parallel, and a plurality ofplatelike heat transfer bodies spaced apart from one another andarranged in a vertical position in a direction to intersect the coolingwater pipes, each of the heat transfer bodies comprising a plurality ofheat transfer plates extending horizontally and each provided for one orat least two stages of the cooling water pipes, the upper of each pairof heat transfer plates vertically adjacent to each other having a lowerend spaced apart by a predetermined clearance from an upper end of thelower of the pair, each of the heat transfer plates having one or atleast two stages of the cooling water pipes extending therethrough, allof the heat transfer plates or the heat transfer plates other than theplate at the uppermost position each having an upper end face beingpositioned at the same level as, or approximately the same level as,upper ends of outer peripheral surfaces of the cooling water pipespositioned at the uppermost stage and extending through the heattransfer plate.
 2. An absorber for use in absorption chillers accordingto claim 1 wherein said clearance is 2 mm to 3 mm.
 3. An absorber foruse in absorption chillers which has a closed chamber to be suppliedwith an absorbent and a refrigerant vapor and having installed thereinmeans for supplying the absorbent, a cooling water piping systempositioned below the absorbent supplying means and comprising aplurality of cooling water pipes the cooling water pipes extendinghorizontally and being interconnected in series or in parallel, and aplurality of platelike heat transfer bodies spaced apart from oneanother and arranged in a vertical position in a direction to intersectthe cooling water pipes, the cooling water pipes extending through theheat transfer bodies, the heat transfer bodies being arranged with apitch of 3 mm to 15 mm.
 4. An absorber for use in absorption chillersaccording to claim 1 or 3 wherein the heat transfer bodies are each inthe form of a plate corrugated in a vertical direction.
 5. An absorberfor use in absorption chillers according to claim 1 or 3 wherein theheat transfer bodies are each subjected to surface working and therebyformed with ridges and furrows arranged along a vertical direction. 6.An absorber for use in absorption chillers according to claim 1 or 3wherein the heat transfer bodies are each formed with a plurality ofvapor passing apertures.
 7. An absorber for use in absorption chillerswhich has a closed chamber to be supplied with an absorbent and arefrigerant vapor and having installed therein means for supplying theabsorbent, a cooling water piping system positioned below the absorbentsupplying means and comprising a plurality of cooling water pipes, thecooling water pipes extending horizontally and being interconnected inseries or in parallel, and a plurality of platelike heat transfer bodiesspaced apart from one another and arranged in a vertical position in adirection to intersect the cooling water pipes, the cooling water pipesextending through the heat transfer bodies, the absorbent supplyingmeans comprising a downflow distributor for allowing the absorbent toflow down the plurality of heat transfer bodies, and a feeder forsupplying the absorbent to the downflow distributor, the downflowdistributor having one or a plurality of absorbent holes for causing theabsorbent to flow down toward each of the heat transfer bodies, said oneabsorbent hole or each of the absorbent holes having an outletpositioned in proximity to a surface of the heat transfer body.
 8. Anabsorber for use in absorption chillers according to claim 7 wherein thedownflow distributor comprises a plurality of absorbent receptaclesjoined to upper end faces of the respective heat transfer bodies, andeach of the absorbent receptacles extends longitudinally of the upperend.
 9. An absorber for use in absorption chillers according to claim 7wherein the downflow distributor comprises a single absorbent receptacleconnected to all the heat transfer bodies across upper ends thereof anddimensioned to contain the upper ends of all the heat transfer bodies.10. An absorber for use in absorption chillers according to claim 7wherein said one absorbent hole or each of the absorbent holes of thedbwnflow distributor is in the form of a slit having an outlet extendingalong the surface of the heat transfer body.
 11. An absorber for use inabsorption chillers which has a closed chamber to be supplied with anabsorbent and a refrigerant vapor and having installed therein means forsupplying the absorbent, a cooling water piping system positioned belowthe absorbent supplying means and comprising a plurality of coolingwater pipes, the cooling water pipes extending horizontally and beinginterconnected in series or in parallel, and a plurality of platelikeheat transfer bodies spaced apart from one another and arranged in avertical position in a direction to intersect the cooling water pipes,the cooling water pipes extending through the heat transfer bodies, eachof the heat transfer bodies being in the form of a plate corrugated inthe direction of extension of the cooling water pipes in section along avertical plane parallel to the direction of extension of the pipes. 12.An absorber for use in absorption chillers which has a closed chamber tobe supplied with an absorbent and a refrigerant vapor and havinginstalled therein means for supplying the absorbent, a cooling waterpiping system positioned below the absorbent supplying means andcomprising a plurality of cooling water pipes, the cooling water pipesextending horizontally and being interconnected in series or inparallel, and a plurality of platelike heat transfer bodies spaced apartfrom one another and arranged in a vertical position in a direction tointersect the cooling water pipes, the cooling water pipes extendingthrough the heat transfer bodies, each of the heat transfer bodies beingsubjected to surface working and thereby formed with ridges and furrowsarranged in the direction of extension of the cooling water pipes insection along a vertical plane parallel to the direction of extension ofthe pipes.
 13. An absorber for use in absorption chillers which has aclosed chamber to be supplied with an absorbent and a refrigerant vaporand having installed therein means for supplying the absorbent, acooling water piping system positioned below the absorbent supplyingmeans and comprising a plurality of cooling water pipes, the coolingwater pipes extending horizontally and being interconnected in series orin parallel, and a plurality of platelike heat transfer bodies spacedapart from one another and arranged in a vertical position in adirection to intersect the cooling water pipes, the cooling water pipesextending through the heat transfer bodies, each of the heat transferbodies being formed with a plurality of vapor passing aperturespositioned away from an outer peripheral surface of each cooling waterpipe.
 14. An absorber for use in absorption chillers according to any ofclaims 3, 7 or 11 to 13 wherein each of the heat transfer bodiescomprises a single heat transfer plate.